/*++++++++++ metadata ++++++++++*/
header_type measurement_meta_t {
    fields {
    promotion: 1; // indicating variable for resubmit;
    stage: 4; // indicating variable for stage of back inserting;
    digest: 8; // digest for differentiating in ancillary table;
    M1_collision: 4; 
    M2_collision: 4;
    M3_collision: 4;
    A_pred: 4; // output predicate in main sub table 1
    flag1: 32;
    flag2: 32;
    flag3: 32;
    flag: 32; // subtract flag used for judging negative or not
    M1_cnt: 32;
    M2_cnt: 32;
    M3_cnt: 32;
    A_cnt: 8;
    srcip_pred: 4;
    dstip_pred: 4;
    proto_pred: 4;
    }
}
metadata measurement_meta_t m_meta;
/*----------*/
